Vibration phenomenon exists when centrifugal pump is operated as hydraulic turbine. In order to make hydraulic turbine operate stably

the volute outlet of hydraulic turbine was designed with different guide vane numbers; then

the geometric models were established using Pro/e software under different guide vane numbers; the monitoring points were set using ANSYS-CFD software along circumferential and radial directions of volute

and amplitudes of pressure fluctuation within volute of hydraulic turbine were calculated under different guide vane numbers; afterwards

the calculational results of pressure fluctuation were transformed by fast Fourier transform

and the distribution of frequency domain of pressure fluctuation in volute and vibration in hydraulic turbine were analyzed under different guide vane numbers. Investigation results show that the dominant frequency amplitude of pressure fluctuation is minimal along circumferential and radial directions of volute when the guide vane number is equal to 9. With the increase of flow rate

dominant frequency amplitude and maximum fluctuation amplitude of pressure fluctuation of monitorin points of valute along radial direction gradually increase

but the degree of increase gradually decreases with the increase of guide vane numbers. When the volute outlet of hydraulic turbine is designed with a set of guide vanes that the guide vane number is equal to 9

the vibration and noise within hydraulic turbine are effectively reduced

and the stability of hydraulic turbine is enhanced.